1. Field of the Invention
This invention relates to a female coupler for coupling to and uncoupling from a pressurized or non-pressurized male coupler such as those used in hydraulic or pneumatic hookups.
2. Description of the Prior Art
Numerous female couplers are currently available for coupling to and uncoupling from a pressurized or non-pressurized male coupler. However, most of these couplers exhibit hookup problems in pressurized situations because they are not designed to handle occasional large pressure differences between the male check member and the female check member. One such cause of this large pressure difference is the thermal expansion of the fluid in the hydraulic hoses to which the couplers are attached. As the temperature increases, the fluid expands, and this action significantly increases the internal pressure. This problem is especially noticeable in farm implements which tend to be parked in an open field for extended periods of time. The heat from the sun causes the fluid to expand and this makes the coupling and uncoupling process difficult.
A number of prior art couplers have tried to solve this troublesome problem but with only minimal success. One such coupler is the self-relieving fluid coupler which was disclosed by applicant in U.S. patent application, Ser. No. 118,267, filed Feb. 4, 1980, now U.S. Pat. No. 4,249,572, which is a continuation of Ser. No. 927,462, filed on July 24, 1978, abandoned. This earlier application partially eased the coupling problem but not to the extent of the present invention. This earlier application differs from the present invention in that it does not employ a lever-actuatable cam, a piston, or an independent secondary valve means to overcome the internal fluid pressure. In addition, applicant knows of no prior art coupler which incorporates a piston for mechanically overcoming the increase in fluid pressure.
The general object of this invention is to provide a female coupler which is easy to connect to and disconnect from a pressurized or non-pressurized male coupler. A more specific object of this invention is to provide a female coupler with a lever-actuatable cam for easily coupling to and uncoupling from a pressurized male coupler.
Another object of this invention is to provide a lever-actuatable female coupler.
Still another object of this invention is to provide a female coupler with a piston which is able to overcome pressure differentials which occur by the expansion of the fluid in the hydraulic hoses due to increases in temperatures.
A further object of this invention is to provide a reliable and inexpensive female coupler.
Other objects and advantages will become apparent to one skilled in the art based upon the ensuing description.